My understanding is that when you are steering manually, the hydraulic fluid
bypasses the pump so you can turn the wheel freely. When you turn on the
autopilot, a solenoid is used to close off this bypass. It draws about 1
amp and is always on when the pilot is on whether the pump is running or
not. I do not know the mechanical drive accomplishes this, but the power
usage figures for them are lower.


"John Proctor" wrote in message
news:2005012614393516807%lost@nowhereorg...
On 2005-01-24 15:39:49 +1100, "Johnhh" said:

I am looking at installing a new bellow deck autopilot on my 34' sailboat
and I'm looking for opinions.

1, Any thoughts on the pros and cons of mechanical linear drives verses
hydraulic linear drives? My understanding is that the mechanical uses
less power and give better feedback to the wheel when turned off,

2. Raymarine verses Simrad?

John

I replaced a Navico (Simrad) with a Raymarine S1 (ST6001+ control head +
S! controller and pump). The boat had mechanical steering but a hydraulic
actuator and pump. This was original with the boat and I saw no need to
replace it. The pump motor runs only when the computer wants to make a
correction. The system works well. Plus I have the spare Raymarine
hydraulic pump. I purchased online from the US and saved a bundle over
what Raymarine's distributor wanted for the same thing here in Australia.
Easy to install and works well so far (nly 4 months use).

--
Regards,
John Proctor VK3JP, VKV6789
S/V Chagall